This is a detection type barrier that can be used to surround an area in a dome, and allows them to monitor said area remotely.

The barrier itself is twofold in nature: first it create a giant, dome-shaped barrier which surrounds a designated area including the sky above it, as well as below the earth. The sphere has several circles which have the kanji for boundary (界), and "barrier" (結界, kekkai) inscribed in them. The barrier is connected to a second, smaller barrier called a Sensing Water Ball (感知水球, Kanchi Suikyū)[1] which the technique user uses to detect entrants into the barrier as well as maintain the size, and shape barrier. When someone passes through the barrier, the sphere ripples at the point of entry.[2] This sphere is made from water,[3][4] and persons, or chakra is represented as varying-sized blimps.